Nobody with a beginners clue about science thinks anything can be proved, except in math.
Yes. I have in mind for the word "proof" the kind of high likelihood of evidence such as that of accepted theories and laws of science. Proofs exist in philosophy, but science uses epistemological arguments in coming to conclusions.
And you can certainly disprove a scientific hypothesis, so it seems proof and disproof are relevant considerations.
It seems to me it's reasonable to say that it's proven that E = MC^2 or F = MA within the proper domain. New discoveries that disprove these will be outside that domain. Thus, F = MA is still true in the classical domain.
Partial definition of "proof" via Merriam Webster online dictionary:
1 a: the cogency of evidence that compels acceptance by the mind of a truth or a fact
1 b: the process or an instance of establishing the validity of a statement especially by derivation from other statements in accordance with principles of reasoning
Seems my use of the word "proof" matches with the dictionary just fine.